The welldispers and nano-scale of silica sphere were synthesized through sol-gel process by TEOS as the precursor at room temperature. We also can control sphere size with the diameter 60 nm, 180 nm and 300 nm. Moreover, 10 nm thickness of Gd2O3: Eu3+ films were also coated on the silica spheres. Core-shell nanoparicles are characterized by XRD, FE-SEM, and HR-TEM. The results show that the core-shell materials are well-crystal and confirmed as Gd2O3: Eu3+ particles. The PL measurement of the Gd2O3: Eu3+ @SiO2 showed a red-emission at the main wavelength of 615 nm (5D0à7F2).